Printing ink



Patented Jan. 9, 1951 U-NITED STATES PRJNTIN G JINK Joseph "-G.. Gurafdo, Bergen fiounty, N. assignor' to -Sun Chemicazl %Corporation,.-New York, N. 35., a-corporation oiflelamare Noillrawing. ApplicationApril .30, 194.7,

, Serial No. 745,105

tion of 'the'binder material is a modified hetanaphthol *pitch.

" *Another object of the present imrentionis to provide a process for modifying h'etaenaphthol pitch to secure a binder ingredient for finkimaterials which give satisfactory printing .irom half toneplates'withoutfill-in.

Other objects of the present invention will .be apparent from the following descrfiptionand appended claims.

'Moisture setting in. 'izehicle componentcontains a r zatereimmi'scible. binder material dissolved or dispersed. :in :a water- =miscible carrier component, have been successfully :used :in. many field's of lpniinting. .For example, books, magazines, newspapersgand the 30 the. fields of carton. :and Plabel printing wherein in]: .materials are desired which have characteristics of extremely rapid setting totnon-ofisetting, non-esmudging-films and which provide-imprinted films which are substantially odorless. In such tape-10f. printing, "the printing operation -1ordi- .narily is efiected- .from line cuts or ,plates, and almost all Of theprinting is-rconcer-ned with the reproduction upon the base. .material of a solid print. 7

.. -some difliculties have been. encountered, utilizing such inks as have hitherto been availablein the hold of publication printing, for example, books, magazines, newspapers and the like. In such printing operations a considerable proportion of the printing is .eliectediirom half tone. plates, and to secure satisfactory printing, .substantially iaithiul. reproduction .01. the. half. 'to'n'e dots is required without fill-in or the .interyening spaces of .the' non-printedsurface .with

material. 'When such fill-in occurs, the cf.-

le'ctiveness of the half tone printing is objectionably altered in that the reproduction on the .imprinted surf ace contains. in portionsnot intended to'be printed. The result 'i's'apoor print.

4 Claims. (01. LEM-31) glycol-insoluble constituents.

'2' .Bythe presentinvention there is provided an ink material which is 'ofrsuch characteristics that successful printingtfrom half tone plates without objectionableifill-inican be secured and which retains the. desirable characteristics of setting,;as an imprinted film, to non-offsetting, non-smudging: cionditions upon the application of moisture.

- fSuch ink. material contains as a major propor tion of the binder (constituent a modified material secured from beta-naphthol pitch.

Betaenaplithol pitches are still bottoms; ob-

tained in the production of beta naphthol, when the "pure product is-distilled from thecrude mixture obtainedfby the fusion or znaphthol sulfonic acid with alkali hydroxide, 'fol'lowedbyzseparation ofithe crude from therea'ction mixture. In United States Patents Nos. 2,415.;827 and 2,415.,- 828, issued on February I8, I947, in thev name of Ernest D. Lee and assigned to Interohemical Corporation, "there are described ink materials in which beta-naphthol pitch is utilized as-a binder constituent; I have found that inks such as 'those described in the above patents are'not satisfactory-in publicat on printing or in other "printing-in which half tone printing plates are used. .However, it has been found, according to the present invention, that by proper modification of'suchpitchmaterials. inks can'be prepared which are completely satisfactory for such printing from half tone surfaces without objectionabl-efill-in.

I have .found that beta-naphthol pitches generally contain a relatively minor pro ortion of The amount of such constituents generallyis within the range of 0.1 to 2 per cent by weight of the beta-naphthol pitch. Further, I have found that the presence 'ofthis relatively minor amount of glycol-insolubl'e constituent is critically responsible for "the failure of such -be'ta naphthol' pitches, unmodi- Tied, to print properly from half tone printing plates without objectionable fill-in. As a result of my research, I believe that the reason why such unmodified beta-naphthol pitches are un-- satisfactoryis that, upon dissolving or dispersing 'in 'apwa'ter miscible liquid carrier component of the utilized in moisture setting inks, this relatively" minor proportion of ,alycol insoluble constituent does not properly disperse or dissolve inthe liquid carrier component While vehicles prepared, containing such glycol-insolu'b'le' cons'tituents, appear'to be homogeneous, upon printing with "ink "prepared containing such vehicle to components, I have found that unsatisfactory such as the ethyl ether of pitch consists in treating this material with 'a' solvent as dipropylene glycol under conditions such that solution of glycol-soluble ingredients is secured. After solution is secured of those portions of the beta-naphthol pitch which are soluble, the mixture then is treated, satisfactorily by filtration, to separate from the solution,

that portion of the beta-naphthol pitch which is insoluble in the glycol. Upon such treatment I have found that the modified beta-naphthol' pitch furnishes a satisfactory binder material for moisture setting inks characterized by the printing qualities outlined above and by its ability, when used in such inks, to furnish a nonoffsetting, non-smudging film containing pigment, upon the application of moisture to the imprinted film.

' In preparing the ink materials, the lycol solution of modified beta-naphthol pitch, prepared as hereinafter described, may be modified, if necessary, by the addition of additional watermiscible liquid carrier component to provide an ink vehicle of satisfactory viscosity, and coloring materials such as pigments and toners dispersed therein to give an ink of the superior characteristics of the present invention.

Liquid carrier components satisfactory for use in preparing ink material of the present invention include water-miscible materials in which the modified beta-naphthol pitch can be dissolved or dispersed. Examples are glycols, such as ethylene glycol, propylene glycol, 2-methyl-2A- pentanediol and the like, glycol ethers such as the ethyl ether of ethylene glycol, butyl ether of ethylene glycol and the like, esters of glycol ethers such as the acetic acid ester of the ethyl ether of ethylene glycol, polyglycols such as diethylene glycol and dipropylene glycol, polyglycol ethers diethylene glycol and butyl ether of diethylene glycol, esters of polyglycol ethers such as the acetic acid ester of the butyl ether of diethylene glycol, and mixtures-of these materials.

Illustrative of one satisfactory method of,effecting preparation of a modified beta-naphthol pitch is the following example.

Example Forty pounds of beta-naphthol pitch are admixed with sixty pounds of dipropylene glycol and the mixture warmed under agitation conditions,

to efiect solution'of the soluble material present,

which in the case of quantities above described, may satisfactorily be accomplished by stirring the admixture at 100 C. for one hour. Upon completion of this step, the mixture secured then is satisfactorily, the filtration operation can be efiected by adding to the warmed mixture 5 pounds of a diatomaceous silica filter aid and one pound of fullers earth, and thereafterfiltering the admixture in a high pressure compression filter having a circular filter membrane '71 inches v in diameter. comprises a satisfactory ink material of the present inventionl f The filtrate from such operation toning pigments may be employed to Illustrative of an ink material satisfactory for commercial printing containing the above vehicle is the following.

Example 2 Pounds Carbon Bl 10 Vehicle of Example 1 72 Dipropylene glycol 18 the reproduction didnot seem to be clean and sharp.

Other pigment materials may be used in place of the carbon black. Also, with carbon black, give slightly different effects, the toners normally making black print look slightly darker than when carbon black is used alone.

: The modified beta-naphthol pitch also may be employed in conjunction with other binder materials which have satisfactory characteristics for utilization in inks adapted for moisture setting after the printing. Examples of such binde materials are rosin modified by reaction with maleic anhydride, terpenes modified by reaction with maleic anhydride, zein, shellac and analogous binder materials which are soluble or dispersible in the liquid component and insoluble in water.

. In the illustrative Example 1, the quantities of diatomaceous silica filter aid and fullers earth utilized are satisfactory under the particular filtrationconditions set forth. With other quantities of materials and different size filters, other quantities of such materials naturally will be employed to obtain satisfactory filtration-operations. It appears to be desirable to have prescut during such filtration an amount of such filter aid and fullers earth sufiicient to form a layer approximately one inch thick on the filter membrane, using the particular filtering system described by way of illustration.

The efiectiveness of the illustrative filtration method may be'explained on the basis of the nature ofthe glycol-insoluble constituents normally present in unmodified beta-'naphthol pitch. Upon treatments with dipropylene glycol as above set forth, such insoluble constituents form swelled, gelatinous aggregates which quickly plug up ordinary filter membranes and reduce theeffectiveness of the filtration operation. Upon addition of thefilter aid .and fullers earth, a bed of. material is formed which increases the effec- With other methods of filtration, such'nitr aids may not be necessary. What is important is the securing of the removal of such glycol-insoluble constituents from the beta-naphthol pitch 1 tosecure a binder material, which, when utilized in printing inks of the character described, has the superior characteristics upon printing hereinbefore set forth.

Other liquid materials may be utilized in the modification procedure in place of dipropylene glycol. Such materials include the liquid carrier components above described, that is, the water miscible glycols, glycol ethers, esters of glycol ethers, polyglycols, polyglycol ethers and esters of polyglycol ethers. As a matter of economy, it generally has been found satisfactory to utilize, in the modification procedure, the material which is to be employed as the major liquid carrier component of the final ink material, since it appears that the glycol-insoluble constituents of unmodified beta-naphthol pitch are likewise insoluble in such other liquid carrier components.

While the above described examples constitute preferred embodiments of the invention, changes may be made therein without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. An ink material having the propertie of printing without fill-in from half tone printing plates and of setting as an imprinted film, to substantially non-offsetting, non-smudging conditions upon the application of moisture thereto, and comprising a binder component anda liquid carrier component, said binder component being beta-naphthol pitch having less than 0.1 per cent by weight of glycol-insoluble constituents, and the liquid carrier component being 2-methyl-2,4- pentanediol.

2. An ink material having the propertie of printing without fill-in from half-tone printing plates and of setting as an imprinted film, to substantially non-ofisetting, non-smudging conditions upon the application of moisture thereto, and comprising a binder component and a liquid carrier component, said binder component being the glycol-soluble extract from beta-naphthol pitch, and the liquid carrier componet being 2- methyl-2,4-pentanediol.

3. An ink material having the properties of printing without fill-in from half-tone printing plates and of setting as an imprinted film, to substantially non-oflsetting, non-smudging conditions upon the application of moisture thereto, and comprising a coloring material dispersed in a vehicle component, said vehicle comprising a binder component and a liquid carrier component, said binder component being beta-naphthol pitch having less than 0.1 per cent by Weight of glycol-insoluble constituents, and the liquid carrier component being 2-methyl-2,4-pentanediol.

4. An ink material having the properties of printing without fill-in from half-tone printing plates and of setting a an imprinted film, to substantially non-offsetting, non-smudging conditions upon the application of moisture thereto, and comprising a coloring material dispersed in a vehicle component, said vehicle comprising a binder component and a liquid carrier component, said binder component being the glycol s luble extract from beta-naphthol pitch, and the liquid carrier component being 2-methyl-2,4-pentanediol.

JOSEPH G. CU'RADO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,002,652 Alexandroff May 28, 1935 2,139,242 Mocls Dec. 6, 1938 2,289,638 Erickson July 14, 1942 2,323,710 Erickson July 6, 1943 2,415,827 Lee Feb. 18, 1947 2,415,828 Lee Feb. 18, 1947 2,449,230 Irion Sept. 14, 1948 OTHER REFERENCES Grempe: Farber Zeitung, 26, (1915), pages 322 and 323. 

1. AN INK MATERIAL HAVING THE PROPERTIES OF PRINTING WITHOUT FILL-IN FROM HALF TONE PRINTING PLATES AND OF SETTING AS AN IMPRINTED FILM, TO SUBSTANTIALLY NON-OFFSETTING, NON-SMUDGING CONDITIONS UPON THE APPLICATION OF MOISTURE THERETO, AND COMPRISING A BINDER COMPONENT AND A LIQUID CARRIER COMPONENT, SAID BINDER COMPONENT BEING BETA-NAPHTHOL PITCH HAVING LESS THAN 0.1 PER CENT BY WEIGHT OF GLYCOL-INSOLUBLE CONSTITUENTS, AND THE LIQUID CARRIER COMPONENT BEING 2-METHYL-,4PENTANEDIOL. 